Protoceratidae
| Protoceratidae | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Graphic representation of Protoceras by Heinrich Harder |
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| Temporal occurrence | ||||||||||||
| middle Eocene (Uintan) to early Pliocene (Hemphillian) | ||||||||||||
| 46 to 5 million years | ||||||||||||
| Locations | ||||||||||||
| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Protoceratidae | ||||||||||||
| Marsh , 1891 | ||||||||||||
The Protoceratidae are an extinct group of even ungulates that lived in North America from the Middle Eocene to the Early Pliocene . They were never particularly species-rich or numerous.
features
Their most noticeable feature are bony horns, which the males carried over the orbit and behind the nostrils. In later Protoceratiden the nasal horn was often forked in a Y-shape, the paired rear horns curved. The animals' teeth had low crowns and their upper molars were much wider than they were long. Male animals had long canines that were separated from the molars by a diastema . The legs of the Protoceratidaen were relatively short and unspecialized. The ulna and radius were only fused together in the advanced Synthetocertini. The second and fifth toes were barely regressed. These features suggest that the animals were not fast runners and may have lived in densely forested or swampy areas where a fast escape rate was not so important.
External system
As a sister group and next extant relatives of protoceratidae apply to different phylogenetic either the analysis ruminants (ruminant) or Camels (Camelidae). The morphology of the animals and stratigraphic data suggest a relationship with the camels.
Internal system
Today 13 genera are recognized. No new genus has been described since 1998.
- Basal Protoceratidae (formerly classified as the subfamily Leptotragulinae)
- Leptotragulus , Eocene
- Leptoreodon , Eocene
- Poabromylus , Eocene
- Toromeryx , Eocene
- Heteromeryx , Eocene
- Pseudoprotoceras , Oligocene
- Subfamily Protoceratinae
- Protoceras , Oligocene
- Paratoceras , Oligocene
- Subfamily Synthetoceratinae
- Tribe Kyptocertini
- Syndyoceras , early Miocene
- Kyptoceras , Miocene, earliest Pliocene
- Tribus Synthetocertini
- Lanbdoceras , early Miocene
- Prosynthetoceras , early Miocene
- Synthetoceras , Miocene
- Tribe Kyptocertini
literature
- Donald R. Prothero, Scott E. Foss (Eds.): The Evolution of Artiodactyls. Johns Hopkins University Press, Baltimore MD 2007, ISBN 978-0-8018-8735-2 .
